What are the allegations against Qatar?

In September, a Guardian investigation found that dozens of Nepalese migrant labourers had died working in Qatar through the summer, many of them young men dying from heart attacks.

The investigation also found that many thousands more were working in "forced labour" conditions, physically abused, often unpaid for months at a time, undocumented and at the whim and mercy of subcontractors. It said much of the abuse was made possible by the idiosyncratic "kafala" sponsorship system.

What is kafala?

The kafala sponsorship system requires all unskilled labourers to have a sponsor, meaning migrant workers are unable to enter the country, leave it or change jobs without their company's permission.

What was the wider reaction to the allegations?

The International Labour Organisation, a UN agency, said Qatar had much to do to meet proper international norms and that "many of the abuses that take place which can lead to forced labour are still happening".

The British government said it should be a precondition of delivering any major sports event that the highest standards of health and safety are enforced.

The International Trade Union Confederation (ITUC) warned that at least 4,000 workers would die between now and the time the first ball is kicked at World Cup 2022 if Qatar did not change working practices.

What has been the Qatari response?

Following the investigation, the Qataris said it was concerned and would conduct an investigation. Since then, however, they have denied the allegations of brutal working conditions, long hours, lack of food and pay and squalid living conditions.

What has Fifa said?

The world football body's president, Sepp Blatter, has avoided the question and last week even appeared to suggest that the Guardian reports were produced by journalists who had not even visited Qatar. The Guardian flatly rejected that suggestion.